Fasting blood glucose (FBG) levels obtained at hospital admission were associated with mortality and poor early outcomes among patients with COVID-19 infection, according to results of a study, published in the International Journal of Infectious Diseases.
This retrospective cohort study included data captured from patients hospitalized with COVID-19 infection at the Wuhan Union Hospital and Wuhan Red Cross Hospital in China between January and April 2020. The researchers aimed to determine the relationship between FBG levels and outcomes of COVID-19 infection. The primary outcomes included in-hospital mortality, postdischarge mortality, transfer to an intensive care unit (ICU), and intubation.
Among the 2555 patients included in the analysis, 212 died of COVID-19 infection. Of patients who survived and those who died, the median age was 59.0 (IQR, 47.0-67.0) and 69.0 (IQR, 62.0-78.0) years (P <.0001), 45.8% and 70.8% were men (P <.0001), 13.6% and 27.8% had cardiovascular disease (P <.0001), 17.9% and 36.8% had diabetes (P <.0001), and 2.2% and 9.4% had chronic kidney disease (P <.0001), respectively.
Among patients who died during hospitalization, receipt of oxygen therapy via high-flow nasal cannula, noninvasive mechanical ventilation, antibiotics, and corticosteroids was more likely compared with those who survived (all P <.0001).
The researchers found that patients with hypoglycemia and hyperglycemia had an increased risk of mortality. However, the risk of mortality was most increased among patients whose FBG levels were 10.0 mmol/L or more (adjusted hazard ratio [aHR], 4.44; 95% CI, 2.59-7.62). Further analysis showed a J-shaped association between FBG levels above the optimal target range of 4.0 to 6.1 mmol/L and the risk of mortality.
Similar findings were observed in regard to the risk for poor early outcomes, including ICU transfer and the need for intubation. The risk for poor early outcomes increased linearly among patients whose FBG levels were more than 5.0 mmol/L, with the greatest risk observed among those whose FBG levels were 10.0 mmol/L or more (aHR, 3.72; 95% CI, 2.25-6.15).
The association between FBG levels above 5.0 mmol/L and an increased mortality risk was most evident in patients younger than 65 years (P =.054), as well as among women (P <.001) compared with men.
Of patients with hyperglycemia, those with increased concentrations of C-reactive protein (HR, 25.31), interleukin-6 cytokines (HR, 25.09), lactate dehydrogenase (HR, 16.46), procalcitonin (HR, 11.51), D-dimer (HR, 7.39), and a high neutrophil-lymphocyte ratio (HR, 16.07) had a significantly increased mortality risk.
This study was limited by its retrospective design and the small number of patients with hypoglycemia.
According to the researchers, the strong joint effects between FBG levels and hyperglycemia, inflammation, coagulation, and cytokines “might provide new insights on the role of FBG [in regard to] mortality and poor early outcomes in patients [with COVID-19 infection.”
Lai X, Deng S, Hu L, et al. J-shaped associations and joint effects of fasting glucose with inflammation and cytokines on COVID-19 mortality. Int J Infect Dis. 2022;122:285-294. doi:10.1016/j.ijid.2022.05.060